[Feature] New JFXButton type (Outlined Button)

[skmedix]

https://material.io/design/components/buttons.html#outlined-button

[jfoenixadmin]

@skmedix the outlined button can be done through css by using a Flat JFXButton with a border color.

JFXButton types are FLAT / RAISED:

• FLAT button is a simple normal button
• RAISED button has a shadow attached to it, when clicked the button shadow will be animated to simulate raise animation.

[skmedix]

I agree, technically there's not difference, but we should provide that style too, especially when it's official button type. https://material.io/design/components/buttons.html#usage